U.S. patent application number 13/591076 was filed with the patent office on 2013-02-28 for cooling system and method.
This patent application is currently assigned to FORD GLOBAL TECHNOLOGIES, LLC. The applicant listed for this patent is Bernd Brinkmann, Jan Mehring, Hans Guenter Quix. Invention is credited to Bernd Brinkmann, Jan Mehring, Hans Guenter Quix.
Application Number | 20130047940 13/591076 |
Document ID | / |
Family ID | 47741812 |
Filed Date | 2013-02-28 |
United States Patent
Application |
20130047940 |
Kind Code |
A1 |
Quix; Hans Guenter ; et
al. |
February 28, 2013 |
COOLING SYSTEM AND METHOD
Abstract
A cooling system for an engine. The cooling system includes a
flow control element including an inlet in fluidic communication
with an outlet of a cylinder head water jacket, a first outlet port
in fluidic communication with a heat exchanger, and a second outlet
port in fluidic communication with an inlet of an engine block
water jacket.
Inventors: |
Quix; Hans Guenter;
(Herzogenrath, DE) ; Mehring; Jan; (Koeln, DE)
; Brinkmann; Bernd; (Dormagen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Quix; Hans Guenter
Mehring; Jan
Brinkmann; Bernd |
Herzogenrath
Koeln
Dormagen |
|
DE
DE
DE |
|
|
Assignee: |
FORD GLOBAL TECHNOLOGIES,
LLC
Dearborn
MI
|
Family ID: |
47741812 |
Appl. No.: |
13/591076 |
Filed: |
August 21, 2012 |
Current U.S.
Class: |
123/41.08 ;
123/41.02; 123/41.82R |
Current CPC
Class: |
F01P 7/165 20130101;
F01P 2003/027 20130101 |
Class at
Publication: |
123/41.08 ;
123/41.82R; 123/41.02 |
International
Class: |
F01P 7/16 20060101
F01P007/16; F02F 1/36 20060101 F02F001/36 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 23, 2011 |
EP |
11178430.2 |
Aug 23, 2011 |
EP |
11178432.8 |
Claims
1. A cooling system in an engine comprising: a flow control element
including an inlet in fluidic communication with an outlet of a
cylinder head water jacket, a first outlet port in fluidic
communication with a heat exchanger, and a second outlet port in
fluidic communication with an inlet of an engine block water
jacket.
2. The cooling system of claim 1, where the flow control element
adjusts coolant flow through the first and second outlet ports
based on coolant temperature, the cooling system without a bypass
around the heat exchanger, the bypass from the outlet of the
cylinder head water jacket to the inlet of the engine block water
jacket.
3. The cooling system of claim 1, where the flow control element
increases coolant flow through the first outlet port and decreases
coolant flow through the second outlet port in response to an
increase in coolant temperature.
4. The cooling system of claim 1, where the flow control element is
controlled by a controller.
5. The cooling system of claim 1, where the flow control element
comprises a thermostat and a valve, the valve adjusting coolant
flow to at least one of the inlet of the engine block water jacket
and the inlet of the heat exchanger and the thermostat adjusting
coolant flow to the inlet of the heat exchanger.
6. The cooling system of claim 5, where the thermostat includes a
fourth outlet port and the valve adjusts coolant flow to the inlet
of the engine block water jacket and the inlet of the heat
exchanger.
7. The cooling system of claim 5, where the outlet of the cylinder
head water jacket includes a first outlet port in direct fluidic
communication with the thermostat and a second outlet in direct
fluidic communication with the valve.
8. The cooling system of claim 1, where coolant lines leading from
an outlet of the engine block water jacket and an outlet of the
heat exchanger fluidly merge and lead to an inlet of a pump.
9. The cooling system of claim 8, where the pump includes a sole
outlet port in fluidic communication with an inlet of the cylinder
head water jacket.
10. A split coolant circuit in an internal combustion engine
comprising: a pump; a cylinder head water jacket including an inlet
in fluidic communication with an outlet of the pump; an engine
block water jacket including an inlet in fluidic communication with
an outlet of the cylinder head water jacket; a heat exchanger
including an outlet in fluidic communication with an inlet of the
pump and an inlet in fluidic communication with the outlet of the
cylinder head water jacket; and a flow control element coupled to
the outlet of the cylinder head water jacket, the flow control
element including a first outlet port in fluidic communication with
an inlet of the engine block water jacket, a second outlet port in
fluidic communication an inlet of a first heat exchanger, and a
third outlet port in fluidic communication with an inlet of a
second heat exchanger.
11. The split coolant circuit of claim 10, where the engine block
water jacket flows coolant in an opposite direction as coolant flow
in the engine block water jacket.
12. The split coolant circuit of claim 10, further comprising a
connecting coolant line in fluidic communication with an outlet of
the engine block water jacket and an inlet of the pump, the
connecting coolant line opening into a line downstream of the first
heat exchanger.
13. The split coolant circuit of claim 10, where flow control
element includes a thermostat and a proportional valve in parallel
fluidic communication with the outlet of the cylinder head water
jacket, the proportional valve including the first outlet port, the
second outlet port, and the third outlet port, and where the outlet
of the cylinder head water jacket includes a first outlet port in
direct fluidic communication with the thermostat and a second
outlet port in direct fluidic communication with the proportional
valve.
14. The split coolant circuit of claim 13, where the thermostat
includes a fourth outlet port in fluidic communication with the
inlet of the first heat exchanger and where connecting coolant
lines from the second outlet port and the fourth outlet port
fluidly merge upstream of the first heat exchanger.
15. The split coolant circuit of claim 13, where the thermostat and
the proportional valve are independently adjustable.
16. The split coolant circuit of claim 13, where the thermostat
adjusts the coolant flow through the thermostat when coolant
temperature exceeds a threshold value.
17. The split coolant circuit of claim 10, where the second heat
exchanger is a cabin heater and the first heat exchanger is a
radiator.
18. A method, comprising: flowing a first coolant portion from a
cylinder head outlet to a radiator through a first line; flowing a
second coolant portion the cylinder head outlet to an engine block
inlet through a second line, without flowing any coolant in a
bypass around the radiator; and adjusting magnitudes of the first
and second coolant portions based on an engine temperature via a
valve communicating with the cylinder head outlet.
19. The method of claim 18, further comprising flowing coolant from
an engine block outlet to a pump inlet and flowing coolant from a
pump outlet to a cylinder head inlet, without coolant flowing
through any other paths of the cylinder head, engine block, and
radiator.
20. The method of claim 18, further comprising flowing a third
coolant portion from the cylinder head outlet to a heater when the
engine is below at least one of a threshold operating temperature
and engine load.
21. The method of claim 18, where adjusting the magnitudes of the
first and second coolant portions includes, when coolant in the
cylinder head water jacket is below a threshold temperature,
inhibiting coolant flow to at least one of the engine block inlet
and a radiator inlet from the cylinder head water jacket and when
coolant in the cylinder head water jacket is above a threshold
temperature, permitting coolant flow to at least one of the engine
block inlet and the radiator inlet from the cylinder head water
jacket.
22. The method of claim 18, where adjusting magnitudes of the first
and second coolant portions is also based on engine load.
23. The method of claim 18, further comprising flowing a third
coolant portion from a second cylinder head outlet to the radiator
through a thermostat and a third line.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to European Patent
Application Number 11178432.8 filed on Aug. 23, 2011 and European
Patent Application Number 11178430.2 filed on Aug. 23, 2011, the
entire contents of each of which are hereby incorporated herein by
reference for all purposes.
BACKGROUND/SUMMARY
[0002] Internal combustion engines may include engine blocks and
cylinders heads. Each of the engine block and the cylinder head may
be traversed by separate coolant circuits or at least predominantly
separated cooling circuits. This engine cooling arrangement may be
referred to as a split cooling system. In this way, the cylinder
head, which may be thermally coupled to the combustion chamber
wall, the intake manifold, and the engine block, which is thermally
coupled to the friction points, can be cooled differently, if
desired. The split cooling system (e.g., split coolant circuit) may
attempt to cool the cylinder head during a warm-up period while
reducing or in some cases inhibiting cooling of the engine block so
that the engine block may achieve a desired operating temperature
more quickly. In other words, the split coolant circuit may be
thought of as a single cooling circuit for an engine in which the
water jacket in the cylinder head is separated from the water
jacket in the engine block via suitable mechanisms. In some
embodiments, however, there may be low levels of leakage from the
cylinder head water jacket to the engine block water jacket,
wherein the leakage quantities are so small that one can
nevertheless refer to this as a split coolant circuit.
[0003] FR 2 860 833 A1 discloses a cooling circuit of an internal
combustion engine having at least one cylinder head and a cylinder
housing, said cooling circuit being composed of at least three
cooling passages. The circuit has a heat exchanger, a driver for a
heat exchange medium, and at least one controller for controlling
the flow of heat exchange medium through the cylinder head, the
cylinder housing or the heat exchanger. The cooling circuit has at
least three independent passages for engine cooling, wherein the
first and second passages are arranged in the cylinder head and the
third passage is arranged in the cylinder housing, and wherein the
passages are independent of one another and comprise at least one
inlet and one outlet, such that they permit an independent flow of
the heat exchange medium through each of the passages of the
cylinder head and of the cylinder housing. FR 2 860 833 A1
discloses that three controllers (e.g., valves) are provided in
order to be able to regulate different circulations of the heat
exchange medium. One controller is arranged at the inlet side and
one controller is arranged at the outlet side. The third controller
is connected to the other two controllers.
[0004] U.S. Pat. No. 5,385,123 discloses a split coolant circuit
having a single thermostat which, in one embodiment, is arranged in
an outlet line of the outlet side of a cylinder head to a pump, the
line of which opens out at the inlet side in the cylinder head. A
bypass and a block line branch off from the outlet line and extend
into the engine block. The bypass leads to the pump. In the
aforementioned embodiment, the thermostat is arranged in the branch
of the three lines. During the warm-up phase, the thermostat closes
the block line, wherein the bypass is fully open. When the
thermostat is closed, the coolant flows through the bypass to the
pump, and from there into the cylinder head. As the coolant
temperature rises, the thermostat successively closes the bypass,
such that the direct flow in the direction of the pump is
continuously reduced, and is completely shut off when the bypass is
completely closed. The coolant then flows out of the cylinder head
through the outlet line and the block line into the engine block,
which is connected to a cooler, and from there to the pump.
[0005] The Inventors have recognized several disadvantages with the
split cooling design in U.S. Pat. No. 5,385,123 and the cooling
system disclosed in FR 2 860 833. Firstly, the cooling systems
disclosed in U.S. Pat. No. 5,385,123 and FR 2 860 833 may be bulky,
thereby reducing the engine's compactness and increasing the size
and cost of the engine. As a result, the cost of the engine may be
increased. Moreover, the control system for controlling the 3
independent engine cooling passages in FR 2 860 833 may be complex
and costly.
[0006] To solve at least some of the aforementioned problems a
cooling system for an engine is provided. The cooling system
includes a flow control element having an inlet in fluidic
communication with an outlet of a cylinder head water jacket, a
first outlet port in fluidic communication with a heat exchanger,
and a second outlet port in fluidic communication with an inlet of
an engine block water jacket.
[0007] In this way, the coolant may be flowed from the outlet of
the cylinder head water jacket to the inlet of the engine block
water jacket during some operating conditions and/or from the
outlet of the cylinder head water jacket to a heat exchanger during
other operating conditions. As a result, coolant may be flowed in
series through the cylinder head and the engine block bypassing the
heat exchanger, enabling a heater bypass line to be omitted from
the cooling system, if desired. Moreover, the flow control element
may be used to separately adjust the coolant flow through both the
cylinder head water jacket and the cylinder block water jacket
based on the engine's operating conditions.
[0008] The above advantages and other advantages, and features of
the present description will be readily apparent from the following
Detailed Description when taken alone or in connection with the
accompanying drawings. It should be understood that the summary
above is provided to introduce in simplified form a selection of
concepts that are further described in the detailed description. It
is not meant to identify key or essential features of the claimed
subject matter, the scope of which is defined uniquely by the
claims that follow the detailed description. Furthermore, the
claimed subject matter is not limited to implementations that solve
any disadvantages noted above or in any part of this
disclosure.
BRIEF DESCRIPTION OF THE FIGURES
[0009] FIG. 1 shows a diagrammatic illustration of a split coolant
circuit;
[0010] FIG. 2 shows a graph depicting an example of the control of
the flow control element; and
[0011] FIG. 3 shows a method for operation of a cooling system in
an engine.
[0012] The figures are described in greater detail below.
DETAILED DESCRIPTION
[0013] A split coolant circuit is described herein. The split
coolant circuit includes a flow control element arranged on an
outlet housing of a cylinder head water jacket. The flow control
element may include a thermostat and a proportional valve which is
separate from said thermostat. Furthermore, the thermostat may be
connected in a parallel flow configuration with the proportional
valve. Additionally, the proportional valve may have an engine
block connecting coolant line coupled thereto leading to the engine
block water jacket, a heater connecting coolant line coupled
thereto leading to a heater, and a cooler connecting line coupled
thereto leading to a cooler. Additionally, the thermostat may also
have a connecting coolant line coupled thereto and leading to the
cooler. However, other coolant circuit configurations have been
contemplated.
[0014] In some examples, coolant from the cylinder head water
jacket may be flowed directly into the block water jacket. Such an
arrangement enables a bypass line positioned upstream and
downstream of the cooler (e.g., from the thermostat to the block
entrance, bypassing the radiator) to be omitted, if desired. As a
result, the cost of the split coolant circuit may be decreased. In
such an example, the engine block water jacket may perform the
function of the aforementioned bypass line, if desired,
specifically that of bypassing the cooler, such that the coolant is
not cooled unnecessarily, for example in the warm-up phase of the
internal combustion engine. This may lead to higher material and
also oil temperatures, as a result of which friction and thermal
losses are reduced. In this way, the engine may be brought up to a
desired temperature more quickly and after the desired operating
temperature achieved adjustable amounts of cooling may be provided
to both the cylinder head and the engine block. As a result, engine
fuel consumption and engine emissions may be reduced, thereby
increasing the longevity of the internal combustion engine.
[0015] Furthermore, an oppositely-directed coolant flow pattern in
the two separate cooling regions (e.g., the cylinder head water
jacket and the engine block water jacket) may also be used in some
examples. In the cylinder head water jacket, the coolant flows from
the inlet side to the outlet side. In contrast, the coolant is
supplied to the block water jacket at that side which corresponds
to the outlet side of the cylinder head water jacket. In the engine
block water jacket, therefore, the coolant flows, as it were, in
the reverse direction, from the outlet side to the inlet side, in
relation to the flow direction in the cylinder head water
jacket.
[0016] It will be appreciated that the cylinder head water jacket
and the engine block water jacket may not transfer coolant at
points between the inlet and the outlet of each respective water
jacket. Specifically, the cylinder head water jacket and the engine
block water jacket may be coupled in a series flow configuration.
Moreover, the flow through each water jacket may be substantially
in opposite directions. That is to say, that the inlet of the
engine block water jacket may be on the same side of the engine as
the outlet of the cylinder head water jacket, in some examples.
Likewise, the outlet of the engine block water jacket may be on the
same side of the engine as the inlet of the cylinder head water
jacket, in some examples.
[0017] A pump connecting coolant line may connect the pump to the
inlet of the cylinder head water jacket. In this way, the coolant
can pass out of the cylinder head water jacket into the outlet
(e.g., outlet housing) of the cylinder head water jacket.
Furthermore, a heater line may lead to the heater may branch off
from the proportional valve. The heating return line opens out,
upstream of the pump, in a cooler return line which is in fluidic
communication with the pump.
[0018] The return coolant (e.g., water) line which leads out of the
block water jacket likewise is in fluidic communication with cooler
return line, likewise upstream of the pump. In contrast, the
connecting coolant line which leads out of the thermostat
advantageously issues into the cylinder head coolant (e.g., water)
line upstream of the cooler. Further components of the coolant
circuit may be provided. For example, a ventilation device may be
provided which is connected to the heater line and to the cooler,
and the return line of which likewise flows into the cooler return
line upstream of the pump.
[0019] In some examples the thermostat, which functions as a
part-load thermostat, may be connected to the cooler via the
connecting line, wherein the connecting line flows into the cooler
line upstream of the cooler but downstream of the proportional
valve, wherein the engine block water jacket bypasses the cooler
and opens out directly in the cooler return line.
[0020] Further in some examples, a flow control element (e.g., the
proportional valve and the thermostat) may be switchable as a
function of operating modes of the internal combustion engine. One
operating mode of the engine may be a warm-up phase when the engine
is below a predetermined threshold temperature. Another operating
mode may be a "warm" phase when the engine has reached or surpassed
the predetermined threshold temperature. The flow control element
may also be adjusted based on (e.g., as a function of) the load on
the internal combustion engine and/or the power output of the
internal combustion engine. There may be a partial-load mode of
operation as well as a high load mode of operation.
[0021] In a warm-up mode of the internal combustion engine when the
engine is operated with a partial load, all the paths of the
proportional valve, that is to say the path to the engine block
coolant line, the path to the heater line and the path to the
cooler line of the proportional valve and also the thermostat to
the connecting line, are closed. In said state, the split coolant
circuit has, as it were, a flow with a magnitude of zero both in
the block water jacket and also in the head water jacket. The
coolant temperature may be less than 60.degree. C. Thus, the
threshold operating temperature for the warm-up mode may be
60.degree. C.
[0022] In some examples, when the coolant temperature has a
magnitude of greater than 60.degree. C. and less than 75.degree.
C., the path of the proportional valve to the heater line opens in
a continuous fashion until it is completely open. The no-flow
strategy of the cylinder head water jacket is ended, and a partial
flow of the coolant flows out of the outlet housing via the
proportional valve into the heater line, in this example. The path
to the block water line remains closed, such that the coolant flow
in the block water jacket has a magnitude of zero, in this example.
The flow through the cylinder head water jacket may be of a
magnitude which can also flow through the heater line, in this
example. In this respect, the coolant flow in the cylinder head
water jacket is relatively small, which promotes improved warm-up
behavior. The heater can nevertheless provide desired heating to
the vehicle cabin.
[0023] In some examples, when the coolant temperature has a
magnitude of greater than 75.degree. C. and less than 85.degree.
C., the path to the heater line is completely open, wherein the
path to the block water line opens in a continuous fashion. With
the end of the no-flow strategy, a small coolant flow may be
permitted in the block water jacket, in this example. The path to
the cooler line remains closed, in this example.
[0024] Further in some examples, when the coolant temperature has a
magnitude of greater than 85.degree. C. and less than 100.degree.
C., the path to the heater line is fully open as before. In
contrast, the path to the block water line may controlled by the
proportional valve such that the block temperature can be set to a
high magnitude, for example to over 105.degree. C., preferably to
approximately 115.degree. C., in this example. The thermostat may
continue to close the path to the connecting line when the coolant
temperature in the outlet housing or in the cylinder head water
jacket lies below for example 100.degree. C. or preferably below
105.degree. C., in this example.
[0025] When the warm-up phase has come to an end, the control
components may then be controlled as a function of the operating
state "engine at operating temperature and partial load", in some
examples. In said operating mode, that is to say in the case of an
internal combustion engine which is above a threshold temperature
(e.g., "warm") and being operated at partial load, the path to the
heater line may be open, and the path to the block water line may
be regulated such that the block water temperature can be set to a
high magnitude of for example 115.degree. C. If the coolant in the
cylinder head water jacket or in the outlet housing has a magnitude
of greater than 100.degree. C., the thermostat to the connecting
line may open. The coolant flow in the cylinder head water jacket
is thus further increased, in this example. Since an additional
part of the cylinder head coolant flow is thus conducted via the
main cooler, the temperature in the cylinder head water jacket can
be easily regulated, below the opening temperature, in some
examples. The coolant flow may be controlled by the thermostat
(e.g., opening temperature for example 100.degree. C.) together
with the proportional valve when the internal combustion engine is
at its operating temperature and is being operated in part load, in
some examples. Therefore, the thermostat may be designed as a
part-load thermostat, and is configured to open in part-load
operation when the temperature in the cylinder head water jacket or
in the outlet housing has a magnitude greater than its opening
temperature, in some examples. However, other thermostat operating
schemas have been contemplated.
[0026] In part-load operation, the internal combustion engine may
be operated with elevated temperature in both regions
independently, in some examples. However, other control techniques
have been contemplated.
[0027] The path of the proportional valve to the cooler line may be
opened if needed when, for example, the internal combustion engine
is operated at relatively high load. For this purpose, the
proportional valve may open the line to the main cooler to regulate
the temperature of the cylinder head water jacket to, for example,
85.degree. C. The part-load thermostat may then be closed, because
the opening temperature is not reached. The branch to the block
water jacket is then fully open, in this example. The path may be
regulated such that the coolant temperature in the block water
jacket is below a predetermined threshold value, for example
regulated to a magnitude of 90.degree. C., because the engine block
may have a greater cooling need at relatively high load of the
internal combustion engine.
[0028] In the event of a malfunction of the proportional valve and
therefore an inadequate coolant flow to the main cooler, the
part-load thermostat also may have a protective function. In this
case, in the event of an increase in the coolant temperature above
the opening temperature, the part-load thermostat may open and
conduct coolant to the main cooler. The part-load thermostat may
also function as a safety thermostat because excessive overheating
is prevented by opening in the direction of the cooler, in some
examples.
[0029] A further operating state or operating mode may be the
internal combustion engine is operated in the warm-up phase at high
load. In said operating mode, the path to the heater line is
completely open, wherein the path to the block water line may be
regulated by the proportional valve. The path may be regulated such
that the coolant temperature in the block water jacket is below a
predetermined threshold value, for example regulated to a magnitude
of 90.degree. C., because the engine block may have high cooling
demand at full load of the internal combustion engine. The coolant
flow in the cylinder head water jacket may be regulated by the
proportional valve, wherein a temperature of 85.degree. C. can be
set in the cylinder head water jacket.
[0030] A further operating mode may be the internal combustion
engine is at its operating temperature and is being operated at
high load or full load. In said operating mode, the path to the
heater line may be closed. This may be implemented if, for example
at high ambient temperatures, the maximum cooling power must be
generated, in some examples. The path to the block water line can
be regulated by the proportional valve. The path may be regulated
such that the coolant temperature in the block water jacket is low,
for example regulated to a magnitude of 90.degree. C., because the
engine block may have a high cooling demand at full load of the
internal combustion engine. The coolant flow in the cylinder head
water jacket may be regulated by the proportional valve, wherein a
temperature of 85.degree. C. can be set in the cylinder head water
jacket, in some examples. The part-load thermostat accordingly may
not open at all because the temperature lies below its opening
temperature. If the temperature nevertheless rises above the
opening temperature, the thermostat may open and perform its
protective function by virtue of coolant additionally being
conducted to the cooler, in some examples.
[0031] If the flow control element (e.g., the two components the
proportional valve and the thermostat (e.g., part load
thermostat)), is as a function of the operating mode a control unit
may be used to implement the aforementioned control strategies. The
control unit may include memory executable by a processor. The
control strategies may be stored via code in the memory. The
control unit may be included in the engine and/or vehicle.
[0032] In some examples, the internal combustion engine (e.g., the
engine block water jacket and the cylinder head water jacket) may
be operated with the "no-flow strategy" for a desired period of
time. In other words, coolant flow may be substantially inhibited
in the engine block and/or the cylinder head. During this mode, the
cabin heater may be supplied by the corresponding path of the
proportional valve being opened. When cabin heating is desired, the
no-flow strategy may be discontinued in the cylinder head water
jacket but may be maintained in the block water jacket.
[0033] In some examples, the coolant inlet temperature as it enters
the engine block may be raised by approximately 3 to 5 K, because
the in-feed takes place from the outlet of the cylinder head
circuit. Furthermore, the engine block temperature, that is to say
the material temperature itself, may be raised because the
temperature may be controlled by the part-load thermostat, and a
reduced coolant flow through the block water jacket may be
generated in some examples. A variable operating temperature may be
set in the cylinder head water jacket in accordance with the
above-stated operating modes, in some examples. At part load, the
temperature may even be raised up to 115.degree. C., if said
temperature is exceeded; the part-load thermostat may open and thus
increases the magnitude of the coolant flow, and conducts a part of
said coolant flow via the cooler, in some examples. The coolant
flow through the heater may also be variable during the warm-up
phase, in some examples. As previously discussed, the coolant flow
in the block water jacket may be in the opposite direction to the
coolant flow in the cylinder head water jacket. Also, the fact that
the coolant which emerges from the cylinder head, and which, as it
were, has been warmed up, is supplied to the block water jacket may
enable the engine block to be thermally managed to reduce friction
losses in some examples.
[0034] In some examples, the proportional valve may only flow a
portion of the coolant travelling therethrough from the cylinder
head water jacket to the engine block water jacket due to the
desired cooling of the engine block may be less than (e.g., 30% to
50% of) the desired cooling power of the cylinder head. Thus, the
engine block temperature may be adjusted via the adjustment in
coolant flow, in some examples. When a portion coolant flow is
conducted via the cooler the heater circuit may be closed, because
the cooling power at the vehicle cooler may be provided at high
ambient temperatures, in some examples. The cabin heater may be
inactive, during such operation. This may lead to a change in the
pressure conditions, and therefore to an increased flow through the
main cooler, in some examples. As a result of the configuration in
which the thermostat permits the coolant flow through the cooler
when the internal combustion engine is at part load or for
protection purposes, the thermostat may be designed, in some
examples, as a single-acting thermostat which opens at relatively
high temperatures, in order thereby to permit increased coolant
temperatures in particular in the cylinder head water jacket,
wherein in other operating modes which differ from this, the
cylinder head coolant temperature can be reduced, that is to say is
variable.
[0035] A cooling system 50 in an engine 52 is shown in FIG. 1. The
cooling system 50 may include a split coolant circuit 1. The split
coolant circuit 1 may include a cylinder head water jacket 2 and an
engine block water jacket 3, a pump 4, a first heat exchanger 6
(e.g., a cooler, a radiator), a flow control element 7, an outlet
housing 8 of the cylinder heat water jacket, and a second heat
exchanger 9 (e.g., a heater, a cabin heater). Furthermore, the
coolant circuit 1 may include a ventilation device 11. The second
heat exchanger 9 includes an outlet 160 in fluidic communication
with an inlet 106 of the pump 4.
[0036] The cylinder head water jacket 2 may be fluidly separated
from the block water jacket 3. That is to say that coolant may not
flow from the engine block water jacket to the cylinder head water
jacket or vice-versa at points in between the inlets and outlets of
the respective water jacket. The cylinder head water jacket 2 may
include one or more coolant passages 54 through which coolant
flows. Arrow 56 denotes the general direction of coolant flow
through the cylinder head water jacket 2. Likewise, the engine
block water jacket 3 may include one or more coolant passages 58
through which coolant flows. Arrow 60 denotes the general direction
of coolant flow through the engine block water jacket 3. However,
it will be appreciated that the cylinder head water jacket and/or
the cylinder block water jacket may have other coolant flow
characteristics. Generally, the flow direction in the split coolant
circuit 1 is indicated via arrows. The cylinder head water jacket 2
includes at least one inlet 62 and at least one outlet 64. The
outlet 64 may be referred to as a cylinder head outlet.
[0037] The outlet 64 may include a first outlet port 66 and a
second outlet port 68. Likewise, the engine block water jacket 3
includes at least one inlet 70 and at least one outlet 72. The
inlet 70 and the outlet 72 may be referred to as a block inlet and
a block outlet, respectively. The flow control element 7 is in
fluidic communication (e.g., direct fluidic communication) with the
outlet 64 of the cylinder head water jacket 2. Specifically, in
some examples, the flow control element 7 may be at least partially
positioned in the outlet housing 8. The flow control element 7 may
include a thermostat 12 and a valve 13 (e.g., proportional valve).
In some examples, the thermostat 12 and the valve 13 may be
separate. However, in other examples, the thermostat 12 and the
valve 13 may be a single apparatus. The thermostat 12 may be
arranged in a parallel flow configuration with the valve 13. That
is to say that the inlets of the thermostat 12 and the valve 13 are
in fluidic communication and the outlets of the thermostat and the
valve are also in fluidic communication. However, other flow
configurations have been contemplated.
[0038] A coolant (e.g., water) line 14 (e.g., block coolant line)
is in fluidic communication with the valve 13 and the engine block
water jacket. Coolant line 14 includes an inlet 74 and an outlet
76. The inlet 74 is in fluidic communication (e.g., direct fluidic
communication) with an outlet port 78 of the flow control element
7. Specifically, the outlet port 78 is in the valve 13. However,
other port positions have been contemplated.
[0039] The split coolant circuit 1 further includes a coolant line
16 (e.g., heater coolant line) in fluidic communication with the
valve 13 and second heat exchanger 9. Thus, the coolant line 16
includes an inlet 81 in direct fluidic communication with an outlet
port 80 of the flow control element 7. Specifically, the outlet
port 80 is in the valve 13. However, other valve positions have
been contemplated. The coolant line 16 also includes an outlet 83
in fluidic communication with an inlet 108 of the second heat
exchanger 9.
[0040] The split coolant circuit 1 further includes a coolant line
17 (e.g., cooler coolant line) in fluidic communication with the
valve 13 and the first heat exchanger 6 (e.g., cooler). Thus, the
coolant line 17 includes an inlet 82 in fluidic communication
(e.g., direct fluidic communication) with an outlet port 84 of the
flow control element 7. Specifically, the outlet port 84 is in
valve 13. The coolant line 17 further includes an outlet 86 in
fluidic communication (e.g., direct fluidic communication) with an
inlet 88 of the first heat exchanger 6.
[0041] The split coolant circuit 1 further includes connecting
coolant line 18 in fluidic communication (e.g., direct fluidic
communication) with the thermostat and the first heat exchanger 6.
The coolant line 18 includes an inlet 90 in fluidic communication
with an outlet port 92 of the flow control element 7. Specifically,
the outlet port 92 is in the thermostat 12. Each of the outlet
ports (78, 80, 84, and 92) may be referred to as a first, second,
third, and/or fourth outlet port depending on the order in which
they are introduced, in some examples. The coolant line 18 merges
with or opens into coolant line 17.
[0042] The thermostat includes an inlet 94 in fluidic communication
with the first outlet port 66 of the cylinder head water jacket 2.
Likewise, the valve 13 includes an inlet 96 in fluidic
communication with the second outlet port 68 of the cylinder head
water jacket 2.
[0043] A coolant line 19 (e.g., pump coolant line) connects the
pump 4 to the inlet side 21 of the cylinder head water jacket 2.
Specifically, an outlet 98 of the coolant line 19 is in fluidic
communication with the inlet 62 of the cylinder head water jacket
2. The coolant line 19 further includes an inlet 100 in fluidic
communication with an outlet 102 of the pump 4. The outlet 102 may
be the sole outlet of the pump 4, in some examples. However, other
pump designs have been contemplated. Additionally, the outlet 102
may be referred to as a pump outlet.
[0044] The first heat exchanger 6 also includes an outlet 104 in
fluidic communication with an inlet 106 of the pump 4. The inlet
106 may be referred to as a pump inlet. The split coolant circuit 1
further includes a return coolant line 23 (e.g., a cooler return
line) in fluidic communication with the inlet 106 of the pump 4 and
an outlet 104 of the first heat exchanger 6.
[0045] The split coolant circuit 1 further includes a return
coolant line 22 in fluidic communication with an outlet 160 of the
second heat exchanger 9 and the inlet 106 of the pump 4. In the
depicted embodiment the return coolant line 22 merges with the
return coolant line 23. Specifically, the return coolant line 22
opens into return coolant line 23. However, other arrangements have
been contemplated.
[0046] The split coolant circuit 1 further includes a return
coolant (e.g., water) line 24. The return coolant line 24 includes
an inlet 110 and an outlet 112. The inlet 110 is in fluidic
communication (e.g., direct fluidic communication) with the outlet
72 of the cylinder block water jacket 3 and the outlet 112 is in
fluidic communication (e.g., direct fluidic communication) with the
inlet 106 of the pump 4. The split coolant circuit 1 further
includes a return line 23 (e.g., cooler return line). The return
line 23 includes an inlet 114 in fluidic communication (e.g.,
direct fluidic communication) with the first heat exchanger 6 and
an outlet 116 in fluidic communication with the return coolant line
24. Thus, the return line 23 and the return coolant line 24 merge
at a location downstream of the heat exchanger. Moreover, the
coolant line 24 extends from the outlet of the engine block water
jacket and the inlet of the pump merge at a location downstream of
the heat exchanger. It will be appreciated that, the return coolant
line 24 may open into return line 23 or vice-versa in some
examples. Furthermore, the connecting coolant line 18 which leads
out of the thermostat 12 is in fluidic communication with the line
17 upstream of the first heat exchanger 6.
[0047] The ventilation device 11 is fluidly connected to the
coolant line 16 and the first heat exchanger 6. Additionally, the
return line 26 of said ventilation device is in fluidic
communication with the return line 23, upstream of the pump 4.
[0048] It will be appreciated that a bypass line of the first heat
exchanger 6 has been omitted from the depicted embodiment. As a
result, the complexity and cost of the cooling system is reduced.
It will be appreciated that the engine block water jacket 3 may
function as a bypass line for the first heat exchanger 6 during
some operating conditions. However, a bypass line may be included
in other embodiments.
[0049] As previously discussed coolant flowing out of the cylinder
head water jacket 2 may be flowed to the engine block water jacket
based on the operating modes of the internal combustion engine.
Additionally, the coolant flow in the block water jacket 3 flows in
the opposite direction to the coolant flow in the cylinder head
water jacket 2, in the depicted embodiment. However, other flow
configurations have been contemplated.
[0050] The coolant is supplied to the block water jacket 3 at the
outlet side in relation to the flow direction in the cylinder head
water jacket 2. The coolant flows through the block water jacket 3
in the opposite direction to the flow direction in the cylinder
head water jacket 2 and emerges at the inlet side in relation to
the coolant flow in the cylinder head water jacket 2, and flows
into the cooler return line 23.
[0051] The coolant temperature may be regulated or controlled by a
proportional valve as a function of operating modes, in some
examples. It will be appreciated that the coolant temperature may
be correlated to engine temperature or vice-versa. In part-load
operation of the internal combustion engine, the coolant
temperature in the cylinder head water jacket 2 may be adjusted by
the thermostat 12. The thermostat 12 may for example have an
opening temperature of 100.degree. C. or even of 115.degree. C. or
a value in between, such that the coolant temperature in the
cylinder head water jacket can be set to said elevated value. When
the internal combustion engine is at full load, the coolant
temperature in the cylinder head water jacket may be set to
approximately 85.degree. C., and for a low temperature of
approximately 90.degree. C. to be set in the block water jacket.
The thermostat may not open at all at said low temperatures, such
that the coolant temperature is controlled solely by the
proportional valve. The operating modes and the temperature control
have already been described above. In some examples, the thermostat
12 adjusts the coolant flow through the thermostat when the coolant
temperature exceeds a threshold value. In this way, the flow
control element may be configured to increase coolant flow through
the outlet port (84 and/or 92) and decreases coolant flow through
the outlet port 78 in response to an increase in coolant
temperature, in some examples. A controller 150 having memory 152
storing code executable by a processor 154 may be included in the
cooling system 50. The operating modes described above may be
stored in code.
[0052] FIG. 2 shows a graph illustrating example coolant flows
through the second heat exchanger (line 27), through the engine
block water jacket (line 28) and through the first heat exchanger
(line 29). The flow rate in liters/min is plotted on the vertical
axis. The opening of the proportional valve 13 in % is plotted on
the horizontal axis.
[0053] In a first phase 31, the flow rate in all of the lines and
in the two water jackets 2 and 3 has a magnitude of zero (no-flow
strategy).
[0054] In a second phase 32, an increasing amount of coolant flows
to the second heat exchanger 9. The coolant flows in the engine
block water jacket 3 and in the first heat exchanger 6 are zero
(no-flow strategy in the block). There is a small coolant flow in
the cylinder head water jacket. The proportional valve 13 opens the
heater line in a continuously variable fashion until the path is
completely open. This corresponds to an overall degree of opening
of the proportional valve 13 of up to 30%.
[0055] In a third phase 33, the no-flow strategy in the block water
jacket is also ended. The proportional valve may open said path in
a continuous fashion. The path to the first heat exchanger 6 is, as
before, closed. This is possible in part-load operation, such that
the temperature control in the cylinder head water jacket may be
achieved by the thermostat 12 (e.g., part-load).
[0056] As can be seen, the flow rate in the engine block water
jacket 3 rises from 0 up to 40 liters/min, wherein in said phase,
the flow through the heater decreases from 25 liters/min to
approximately 20 liters/min. At the end of the third phase, the
proportional valve is approximately 50% open, that is to say the
path to the block water jacket and to the heater is open. In
part-load operation, the temperature in the cylinder head water
jacket may be regulated, and set to a high value, by the part-load
thermostat. If said "threshold temperature" is reached, the
part-load thermostat to the cooler opens.
[0057] If it is now detected that the internal combustion engine is
being operated no longer at part load but rather at full load, the
cylinder head coolant temperature may be regulated, in a fourth
phase 34, to a value of approximately 85.degree. C. The
proportional valve 13 may open into the path to the cooler in a
continuous fashion, such that a flow of up to 120 liters/min passes
through said cooler. The path to the heater can be closed.
[0058] The stated values for the threshold temperatures and for the
coolant flow rates of the proportional valve should self-evidently
be understood to be merely exemplary, and serve merely as exemplary
guideline values which are not in any way intended as being
restrictive. In fact, said values should be determined, but not
ultimately fixed, during the course of engine development.
[0059] Within the context of the invention, the expressions
"substantially" or "approximately" or "circa" mean deviations from
the exact value in each case by +/-10%, preferably by +/-5%, and/or
deviations in the form of changes which have no significance in
terms of function.
[0060] FIG. 3 shows a method 300 for operation of a cooling system
in an engine. The method 300 may be implemented by the engine and
cooling system described above with regard to FIG. 1 or may be
implemented by other suitable engines and cooling systems.
[0061] At 302 the method includes flowing a first coolant portion
from a cylinder head outlet to a radiator through a first line. It
will be appreciated that in some embodiments the first portion of
coolant flow may be substantially zero.
[0062] Next at 304 the method includes flowing a second coolant
portion the cylinder head outlet to an engine block inlet through a
second line, without flowing any coolant in a bypass around the
radiator. It will be appreciated that in some embodiments the
second portion of coolant flow may be substantially zero.
[0063] At 306 the method includes adjusting magnitudes of the first
and second coolant portions based on an engine temperature via a
valve communicating with the cylinder head outlet. In some examples
adjusting the magnitudes of the first and second coolant portions
includes, when coolant in the cylinder head water jacket is below a
threshold temperature, inhibiting coolant flow to at least one of
the engine block inlet and a radiator inlet from the cylinder head
water jacket and when coolant in the cylinder head water jacket is
above a threshold temperature, permitting coolant flow to at least
one of the engine block inlet and the radiator inlet from the
cylinder head water jacket. Further in some examples adjusting
magnitudes of the first and second coolant portions is also based
on engine load. Next at 308 the method includes flowing coolant
from an engine block outlet to a pump inlet and flowing coolant
from a pump outlet to a cylinder head inlet, without coolant
flowing through any other paths of the cylinder head, engine block,
and radiator.
[0064] At 310 the method may include flowing a third coolant
portion from the cylinder head outlet to a heater when the engine
is below at least one of a threshold operating temperature and
engine load. Next at 312 the method may include flowing a fourth
coolant portion from a second cylinder head outlet to the radiator
through a thermostat and a third line.
[0065] Note that the example control and estimation routines
included herein can be used with various engine and/or vehicle
system configurations. The specific routines described herein may
represent one or more of any number of processing strategies such
as event-driven, interrupt-driven, multi-tasking, multi-threading,
and the like. As such, various acts, operations, or functions
illustrated may be performed in the sequence illustrated, in
parallel, or in some cases omitted. Likewise, the order of
processing is not necessarily required to achieve the features and
advantages of the example embodiments described herein, but is
provided for ease of illustration and description. One or more of
the illustrated acts or functions may be repeatedly performed
depending on the particular strategy being used. Further, the
described acts may graphically represent code to be programmed into
the computer readable storage medium in the engine control
system.
[0066] It will be appreciated that the configurations and routines
disclosed herein are exemplary in nature, and that these specific
embodiments are not to be considered in a limiting sense, because
numerous variations are possible. For example, the above technology
can be applied to other types inline engines, opposed engines, V
type engines, etc. The subject matter of the present disclosure
includes all novel and non-obvious combinations and
sub-combinations of the various systems and configurations, and
other features, functions, and/or properties disclosed herein.
[0067] The following claims particularly point out certain
combinations and sub-combinations regarded as novel and
non-obvious. These claims may refer to "an" element or "a first"
element or the equivalent thereof. Such claims should be understood
to include incorporation of one or more such elements, neither
requiring nor excluding two or more such elements. Other
combinations and sub-combinations of the disclosed features,
functions, elements, and/or properties may be claimed through
amendment of the present claims or through presentation of new
claims in this or a related application. Such claims, whether
broader, narrower, equal, or different in scope to the original
claims, also are regarded as included within the subject matter of
the present disclosure.
* * * * *